MFIB Display Enhancements
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Information About MFIB Display Enhancements
MFIB
The MFIB is a platform-independent and routing-protocol-independent library for IPv6 software. Its main purpose is to provide a Cisco platform with an interface with which to read the IPv6 multicast forwarding table and notifications when the forwarding table changes. The information provided by the MFIB has clearly defined forwarding semantics and is designed to make it easy for the platform to translate to its specific hardware or software forwarding mechanisms.
When routing or topology changes occur in the network, the IPv6 routing table is updated, and those changes are reflected in the MFIB. The MFIB maintains next-hop address information based on the information in the IPv6 routing table. Because there is a one-to-one correlation between MFIB entries and routing table entries, the MFIB contains all known routes and eliminates the need for route cache maintenance that is associated with switching paths such as fast switching and optimum switching.
How to Use MFIB Display Enhancements
- Verifying MFIB Operation in IPv6 Multicast
- Resetting MFIB Traffic Counters
- Disabling MFIB on the device
- Disabling MFIB Interrupt-Level IPv6 Multicast Forwarding
Verifying MFIB Operation in IPv6 Multicast
 Note |
Multicast forwarding is automatically enabled when IPv6 multicast routing is enabled. |
DETAILED STEPS
Resetting MFIB Traffic Counters
DETAILED STEPS
Disabling MFIB on the device
Multicast forwarding is automatically enabled when IPv6 multicast routing is enabled. However, a user may want to disable multicast forwarding on the router.
DETAILED STEPS
Disabling MFIB Interrupt-Level IPv6 Multicast Forwarding
MFIB interrupt-level IPv6 multicast forwarding of outgoing packets on a specific interface is enabled on interfaces that support Cisco Express Forwarding. However, you may want to disable MFIB interrupt-level forwarding on a specified interface.
DETAILED STEPS
Configuration Examples for MFIB Display Enhancements
Example: MFIB Display Enhancements
Sample Output from the show ipv6 mfib Command
The following example displays the forwarding entries and interfaces in the MFIB.
Device# show ipv6 mfib
IP Multicast Forwarding Information Base
Entry Flags: C - Directly Connected, S - Signal, IA - Inherit A flag,
AR - Activity Required, D - Drop
Forwarding Counts: Pkt Count/Pkts per second/Avg Pkt Size/Kbits per second
Other counts: Total/RPF failed/Other drops
Interface Flags: A - Accept, F - Forward, NS - Negate Signalling
IC - Internal Copy, NP - Not platform switched
SP - Signal Present
Interface Counts: FS Pkt Count/PS Pkt Count
(*,FF00::/8) Flags: C
Forwarding: 0/0/0/0, Other: 0/0/0
Tunnel0 Flags: NS
(*,FF00::/15) Flags: D
Forwarding: 0/0/0/0, Other: 0/0/0
(*,FF05::1) Flags: C
Forwarding: 2/0/100/0, Other: 0/0/0
Tunnel0 Flags: A NS
Ethernet1/1 Flags: F NS
Pkts: 0/2
(2001:DB8:1:1:200,FF05::1) Flags:
Forwarding: 5/0/100/0, Other: 0/0/0
Ethernet1/2 Flags: A
Ethernet1/1 Flags: F NS
Pkts: 3/2
(*,FF10::/15) Flags: D
Forwarding: 0/0/0/0, Other: 0/0/0
Sample Output from the show ipv6 mfib active Command
The following example displays statistics on the rate at which active IP multicast sources are sending information. The device is switching traffic from 2001:DB8:1:1:200 to FF05::1:
Device# show ipv6 mfib active
Active IPv6 Multicast Sources - sending >= 4 kbps
Group: FF05::1
Source: 2001:DB8:1:1:200
Rate: 20 pps/16 kbps(1sec), 0 kbps(last 128 sec)
Sample Output from the show ipv6 mfib count Command
The following example displays statistics from the MFIB about the group and source. The device is switching traffic from 2001:DB8:1:1:200 to FF05::1:
Device# show ipv6 mfib count
IP Multicast Statistics
54 routes, 7 groups, 0.14 average sources per group
Forwarding Counts: Pkt Count/Pkts per second/Avg Pkt Size/Kilobits per second
Other counts: Total/RPF failed/Other drops(OIF-null, rate-limit etc)
Group: FF00::/8
RP-tree: Forwarding: 0/0/0/0, Other: 0/0/0
Group: FF00::/15
RP-tree: Forwarding: 0/0/0/0, Other: 0/0/0
Group: FF05::1
RP-tree: Forwarding: 2/0/100/0, Other: 0/0/0
Source: 10::1:1:200, Forwarding: 367/10/100/7, Other: 0/0/0
Tot. shown: Source count: 1, pkt count: 369
Group: FF10::/15
RP-tree: Forwarding: 0/0/0/0, Other: 0/0/0
Group: FF20::/15
RP-tree: Forwarding: 0/0/0/0, Other: 0/0/0
Sample Output from the show ipv6 mfib interface Command
The following example displays information about IPv6 multicast-enabled interfaces and their forwarding status. The device is configured for fast switching:
Device# show ipv6 mfib interface
IPv6 Multicast Forwarding (MFIB) status:
Configuration Status: enabled
Operational Status: running
MFIB interface status CEF-based output
[configured,available]
Ethernet1/1 up [yes ,yes ]
Ethernet1/2 up [yes ,? ]
Tunnel0 up [yes ,? ]
Tunnel1 up [yes ,? ]
Sample Output from the show ipv6 mfib summary Command
The following example displays summary information about the number of IPv6 MFIB entries and interfaces:
Device# show ipv6 mfib summary
IPv6 MFIB summary:
54 total entries [1 (S,G), 7 (*,G), 46 (*,G/m)]
17 total MFIB interfaces
Additional References
Related Documents
| Related Topic | Document Title |
|---|---|
| Cisco IOS commands |
|
| IP multicast commands |
|
| IPv6 commands |
Cisco IOS IPv6 Command Reference |
| IPv6 features |
|
| IPv6 addressing and connectivity |
IPv6 Configuration Guide |
Standards and RFCs
| Standard/RFC | Title |
|---|---|
| RFCs for IPv6 |
IPv6 RFCs |
MIBs
| MIB |
MIBs Link |
|---|---|
| No new or modified MIBs are supported, and support for existing MIBs has not been modified. |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
Technical Assistance
| Description | Link |
|---|---|
| The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for MFIB Display Enhancements
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
| Table 1 | Feature Information for MFIB Display Enhancements |
| Feature Name | Releases | Feature Information |
|---|---|---|
| MFIB: Display Enhancements |
12.0(26)S 12.2(18)S 12.3(2)T 12.4 12.4(2)T |
The MFIB: Display Enhancements feature for IPv6 provides an enhanced display of MFIB data to provide better and more complete information for troubleshooting MFIB. The following command was introduced: show ipv6 mfib. |
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Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.
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